By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next- to-leading-order (NLO) contributions to the two-body charmless hadronic decays B^+ →ρ^+η(') and B^0 → ρ^...By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next- to-leading-order (NLO) contributions to the two-body charmless hadronic decays B^+ →ρ^+η(') and B^0 → ρ^0(ω, φ)η('), induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that (a) for B^± → ρ^±η(') (B^0 → ρ^0(ω, φ)η(')decays, the partial NLO contributions to branching ratios are small (large) in magnitude; and (b) the pQCD predictions for ACP^dir(B^± → ρ^±η(')) are consistent with the data, while the predicted .ACP(B^0 → ρ^0(ω)η(')) are generally large in magnitude and could be tested by the forthcoming LHCb experiments.展开更多
The phenomenological non-relativistic quark model (NRQM) has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. Th...The phenomenological non-relativistic quark model (NRQM) has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential (OGEP). An overall agreement is obtained with the experimental masses and decay widths.展开更多
Majorana zero modes in the hybrid semiconductor-superconductornanowire is one of the promising candidates for topologicalquantum computing. Recently, in nanowires with a superconductingisland, the signature of Majoran...Majorana zero modes in the hybrid semiconductor-superconductornanowire is one of the promising candidates for topologicalquantum computing. Recently, in nanowires with a superconductingisland, the signature of Majorana zero modescan be revealed as a subgap state whose energy oscillatesaround zero in magnetic field. This oscillation was interpretedas overlapping Majoranas. However, the oscillation amplitudeeither dies away after an overshoot or decays, sharply oppositeto the theoretically predicted enhanced oscillations for Majoranabound states, as the magnetic field increases. Several theoreticalstudies have tried to address this discrepancy, but arepartially successful. This discrepancy has raised the concernson the conclusive identification of Majorana bound states, andhas even endangered the scheme of Majorana qubits basedon the nanowires.展开更多
In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonie decays of the orbitally P-wave excited Bs meson states Bs*, including the newly found narrow Bs1 ...In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonie decays of the orbitally P-wave excited Bs meson states Bs*, including the newly found narrow Bs1 (5830) andBs2(5840) states, into the (Ds1(2536), Ds2(2573)) doublet are calculated from QCD sum rules. With these universal form factors, the decay rates and branching ratios are also estimated.展开更多
In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar mes...In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (i) The leading order pQCD predictions for the branching ratio Br(B^+→K^+K0^*(1430)^0)are in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered B→K0^*(1430)K decay modes are also presented and will be tested by the LHC experiments; (ii) The annihilation contributions play an important role in these considered decays, for B^0→K0^*(1430)^±K^± decays,for example,which are found to be (1-4)×10^-6.展开更多
Amplitudes for φ(2S) sequential decays into 2(π^+π^-)pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles ...Amplitudes for φ(2S) sequential decays into 2(π^+π^-)pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles in laboratory system. The results can be taken as a reference for measuring the decay of XCJ into at BESⅡ/BEPC in the near future.展开更多
Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles and appear in many extensions of the Standard Model.Taking into account constraints on the free parameters from existing searche...Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles and appear in many extensions of the Standard Model.Taking into account constraints on the free parameters from existing searches and explaining the g-2 deviation,we consider the contributions of ALPs with mass in the range of 1.5GeV展开更多
To solve the/a problem of the Minimal Supersymmetric Standard Model (MSSM), a single field S is added to build the Next Minimal Supersymmetric Standard Model (NMSSM). Vacuum enlarged with non-zero vevs of the neut...To solve the/a problem of the Minimal Supersymmetric Standard Model (MSSM), a single field S is added to build the Next Minimal Supersymmetric Standard Model (NMSSM). Vacuum enlarged with non-zero vevs of the neutral-even CP is the combination of Hu, Hd and S. In the NMSSM, the Higgs sector is increased to 7 (compared with 5 hogs in the MSSM), including three Higgs-which are the even-CP hi,2,3 (mh1〈 mh2〈 mh3), two Higgs-which are odd-CP a1,2 (ma1 〈 ma2) and a couple of charged Higgs H^±. The decays Higgs into Higgs is one of the remarkable new points of the NMSSM. In this paper, we study the decays H^± into W^± and at. The decay width is calculated to one loop vertex correction. The numerical results are also described together with evaluations.展开更多
This paper purposes an explanation for the recent evidence for the violation of lepton universality in beauty-quark decays at CERN’s Large Hadron Collider. A beauty meson (B<sup>+</sup>) transforms into a...This paper purposes an explanation for the recent evidence for the violation of lepton universality in beauty-quark decays at CERN’s Large Hadron Collider. A beauty meson (B<sup>+</sup>) transforms into a strange meson (K<sup>+</sup>) with the emission of either electron-positron (e<sup>+</sup>e<sup>-</sup>) or muon-antimuon (<span style="white-space:nowrap;"><em>μ</em></span><sup>+</sup><em>μ</em><sup>-</sup>). The ratio (<em>R</em><sub>K</sub>) of branching fractions for B<sup>+ </sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>- </sup>and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>-</sup> decays is measured to be <em>R</em><sub>K</sub> = 0.846 instead of 1 in the violation of lepton universality in the Standard Model. This paper proposes that the violation is derived from the binary isotope mixture of two beauty-quarks, b<sub>7</sub> (4979 MeV mass) and b<sub>8</sub> (143,258 MeV mass) whose masses are calculated from the periodic table of elementary particles. b<sub>7</sub> is the observable B, while b<sub>8</sub> is the hidden B to preserve the generation number symmetry between the three lepton family generations and the three quark family generations in the Standard Model. The preservation of the generation number symmetry forbids b<sub>8</sub> to decay into K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>. In the transition state involving the virtual particles (<span style="white-space:nowrap;"><em>γ</em></span>, W± and Z<span style="white-space:nowrap;">°</span>) before the decay, b<sub>7</sub> and b<sub>8</sub> emerge to form the binary isotope mixture from B. The rates of emergence as the rates of diffuse in Graham’s law of diffusion are proportional to inverse square root of mass. The rate ratio between b<sub>8</sub>/b<sub>7</sub> is (4979/143,258)<sup>1/2</sup> = 0.1864. Since b<sub>7</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, while b<sub>8</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and forbidden <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, the calculated ratio (RK) of branching fractions for B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup> and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>- </sup>is 0.5/(0.1864 × 0.5+ 0.5) = 0.843 in excellent agreement with the observed 0.846. The agreement between the calculated RK and the observed RK confirms the validity of the periodic table of elementary particles which provides the answers for the dominance of matter over antimatter, dark-matter, and the mass hierarchy of elementary particles.展开更多
Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays...Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D^(0)→a_(1)(1260)π,D^(0)→π(1300)π,D^(0)→ρ(770)ρ(770),and D^(0)→2(ππ)_(S)are observed in both channels.With the obtained amplitude model,the CP-even fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are determined to be(75.2±1.1_(stat).±1.5_(syst.))%and(68.9±1.5_(stat).±2.4_(syst.))%,respectively.The branching fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are measured to be(0.688±0.010_(stat.)±0.010_(syst.))%and(0.951±0.025_(stat.)±0.021_(syst.))%,respectively.The amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D^(0)→4πwhen used to determine the CKM angleγ(ϕ_(3))via the B^(−)→DK^(−)decay.展开更多
We investigate the two loop electroweak corrections to B meson rare decays B¯→Xsγand B0s→μ+μ−in the minimal supersymmetry standard model(MSSM)extension with two triplets and one singlet(TNMSSM).The new parti...We investigate the two loop electroweak corrections to B meson rare decays B¯→Xsγand B0s→μ+μ−in the minimal supersymmetry standard model(MSSM)extension with two triplets and one singlet(TNMSSM).The new particle contents and interactions in the TNMSSM can affect the theoretical predictions of the branching ratios Br(B¯→Xsγ)and Br(B0s→μ+μ−),and the corrections from two loop diagrams to the process B¯→Xsγcan reach around 4%.Considering the latest experimental measurements,the numerical results of Br(B¯→Xsγ)and Br(B0s→μ+μ−)in the TNMSSM are presented and analyzed.The findings indicate that the results in the TNMSSM can fit the updated experimental data well,and the new parameters Tλ,κ,λ,clearly affect the theoretical predictions of Br(B¯→Xsγ)and Br(B0s→μ+μ−).展开更多
In this study,considering the conservation of isospin in the strong decays,we investigate the strong decays of the pentaquark molecule candidate P_(c)(4312)and its possible higher isospin cousin P_(c)(4330)in the fram...In this study,considering the conservation of isospin in the strong decays,we investigate the strong decays of the pentaquark molecule candidate P_(c)(4312)and its possible higher isospin cousin P_(c)(4330)in the framework of the QCD sum rules.Further,the pole residue of theΔbaryon with isospin eigenstate|II3>=|3/21/2)is obtained.If the possible pentaquark molecule candidate P_(c)(4330)could be determined,it would shed light on the interpretations of the P_(c) states in future experiments.展开更多
There is a long-standing puzzle that the CP violation(CPV)in the baryon systems has never been wellestablished in experiments,while the CPV of mesons have been observed by decades.In this paper,we propose thatthe CpV ...There is a long-standing puzzle that the CP violation(CPV)in the baryon systems has never been wellestablished in experiments,while the CPV of mesons have been observed by decades.In this paper,we propose thatthe CpV of baryon decays can be generated with the rescatterings of a nucleon and a pion into some final states,i.e Nπ→Nπor Nππ.Benelited by the fruitful data of Nπscatterings,we can model-independently analyse the strongphases of b-baryon decays using the partial wave amplitudes of Nπscatterings.Avoiding the most difficult problemof non-perturbative dynamics,it makes a great advantage to predict the CpV of baryon decays with a relatively reli.able understanding of the decay dynamics.We study the processes of∧_(b)^(0)→(pπ^(+)π^(-))h^(-)and(pπ^(0))h^(-)with h=πor K.It is found that the global CPV of the above processes in the invariant mass regions of Nπscatterings are at theorder of several percent.More importantly,the local CPV in some regions of the Dalitz plots can reach the order of 10%,or be even larger.Considering the predicted results and the experimental data samples,we strong suggest tomeasure the CPV of∧_(b)^(0)→(pπ^(+)π^(-))K^(-),which has a large possibility to achieve the first observation of CPV in thebaryon system.展开更多
Using the perturbative QCD approach,we studied the effects of the hadronic structure of photons on the pure annihilation rediative decays B→φγ and B_(s)→(ρ^(0),ω)γ.These decays have small branching fractions du...Using the perturbative QCD approach,we studied the effects of the hadronic structure of photons on the pure annihilation rediative decays B→φγ and B_(s)→(ρ^(0),ω)γ.These decays have small branching fractions due to the power suppression by Λ/mB,which makes them very sensitive to next-leading power corrections.The quark components and the related two-particle distribution amplitudes of a final state photon are introduced.The branching fractions can be enhanced remarkably by factorizable and nonfactorizable emission diagrams.The branching fraction of B→φγ increases by approximately 40 times,and those of B_(s)→ρ^(0)γ and B_(s)→ωγ are on the order of O(10-10).We also note that the ratio of branching fractions of B_(s)→ρ^(0)γ and B_(s)→ωγ is very sensitive to the effects of the hadronic structure of photons.All these results can be tested in future.展开更多
Within the standard model,we have investigated rare Z-boson decays into double heavy quarkonia,Z→VV and Z→VP,with V and P denoting vector and pseudo scalar quarkonia,respectively.It is assumed that the leading-order...Within the standard model,we have investigated rare Z-boson decays into double heavy quarkonia,Z→VV and Z→VP,with V and P denoting vector and pseudo scalar quarkonia,respectively.It is assumed that the leading-order QCD diagrams would give the dominant contributions to these processes,and the corresponding branching fractions,for instance,B(Z→J/ΨJ/Ψ),have been estimated to be approximately 10^(-13)in literature.However,these decays could also happen through electromagnetic transitions Z→Vγ^(*)and Z→Pγ^(*),with the virtual photon transforming into V.Interestingly,the smallness of the vector quarkonium mass can give rise to a large factor m_(Z)^(2)/m_(V)^(2)relative to the QCD contributions,which thus counteracts the suppression from the electromagnetic coupling.We systematically include these two types of contributions in our calculation to predict branching fractions for these decays.Particularly,owing to the virtual photon effects,it is found that B(Z→J/ΨJ/Ψ)will be significantly enhanced,up to 10^(-10).展开更多
In this work,we investigate the quasi-two-body decays B_(c)→D^(*)h→Dπhwithh=(K^(0),π^(0),η,η′)using the perturbative QCD(PQCD)approach.The description of final state interactions of the Dπpair is achieved thro...In this work,we investigate the quasi-two-body decays B_(c)→D^(*)h→Dπhwithh=(K^(0),π^(0),η,η′)using the perturbative QCD(PQCD)approach.The description of final state interactions of the Dπpair is achieved through the two-meson distribution amplitudes(DAs),which are normalized to the time-like form factor.The PQCD predictions on the branching ratios of the quasi-two-body decays B_(c)→D^(*)h→Dπh show an obvious hierarchy:Br(B^(+)_(c)→D^(∗+)K^(0)→D^(0)π^(+)K^(0))=(5.22^(+0.86)_(-0.74))×10^(-6),Br(B^(+)_(c)→D^(∗+)π^(0)→D^(0)π^(+)π^(0))=(0.93±0.26)×10^(-7),Br(B^(+)_(c)→D^(∗+)η→D^(0)π^(+)η)=(2.83^(+0.59)_(-0.52))×10^(-8)and Br(B^(+)_(c)→D^(∗+)η′→D^(0)π^(+)η′)=(1.89+0.40-0.36)×10^(-8).From the invariant mass m Dπ-dependence of the decay spectrum for each channel,one can find that the branching fraction is concentrated in a narrow region around the D*pole mass.Thus,one can obtain the branching ratios for the corresponding two-body decays B_(c)→D^(*+)h under the narrow-width approximation.We find that the branching ratios of the decays B_(c)→D^(*+)h are consistent with the previous PQCD calculations within errors.These predictions will be tested in future experiments.展开更多
Within the framework of perturbative QCD factorization,we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=π,K...Within the framework of perturbative QCD factorization,we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=π,K.We compare our predicted branching ratios for the B_(()(s))→K_(χc0)→Kπ^(+)π-(K^(+)K^(-))decay with available experiment data as well as predictions by other theoretical studies.The branching ratios of these decays are consistent with data and other theoretical predictions.However,in the Cabibbo-suppressed decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=K^(0),π,the values of the branching ratios are of the order of 10^(-7)and 10^(-8).The ratio R_((χ)_(c0))between the decays B^(+)→π^(+)χ_(c0)→π^(+)π^(+)π^(-)and B^(+)→K^(+)χc0→K^(+)π^(+)π^(-)and the distribution of branching ratios for different decay modes in invariant mass are considered in this study.展开更多
Weak radiative hyperon decays,important to test the strong interaction and relevant in searches for beyond the standard model physics,have remained puzzling both experimentally and theoretically for a long time.The re...Weak radiative hyperon decays,important to test the strong interaction and relevant in searches for beyond the standard model physics,have remained puzzling both experimentally and theoretically for a long time.The recently updated branching fraction and first measurement of the asymmetry parameter of Λ→nγ by the BESIII Collaboration further exacerbate the issue,as none of the existing predictions can describe the data.We show in this work that the covariant baryon chiral perturbation theory,with constraints from the latest measurements of hyperon non-leptonic decays,can well describe the BESIII data.The predicted branching fraction and asymmetry parameter for Ξ→Σγ are also in agreement with the experimental data.We note that a more precise measurement of the asymmetry parameter,which is strongly constrained by chiral symmetry and related with that of Σ→pγ,is crucial to test Hara’s theorem.We further predict the branching fraction and asymmetry parameter of Σ~0→nγ,whose future measurement can serve as a highly nontrivial check on our understanding of weak radiative hyperon decays and on the covariant baryon chiral perturbation theory.展开更多
We study two-body B(c)→Mc(π,K) and semileptonic Bc→Mcl^-v^-1 decays with Mc=(J/φ,Xc^0),where Xc^0=X^0(3872) is regarded as the tetraquark state ccuu(dd).With the decay constant fxc^0=(234±52) MeV ...We study two-body B(c)→Mc(π,K) and semileptonic Bc→Mcl^-v^-1 decays with Mc=(J/φ,Xc^0),where Xc^0=X^0(3872) is regarded as the tetraquark state ccuu(dd).With the decay constant fxc^0=(234±52) MeV determined from the data,we predict that B(B^-→Xc^0π^-) =(11.5±5.7)×10^-6,B(B^0→Xc^0K^-0)=(2.1±1.0)×10^-4,and B(Bs^0→Xc^0K^0)=(11.4±5.6)×10^-6.With the form factors in QCD models,we calculate that B(Bc^-→Xc^0π^-,Xc^0K^-)=(6.0±2.6)×10^-5 and(4.7±2.0)×10^-6,and B(Bc^-→J/φμ^-vμ^-vμ,Xc^0μ^-v^-μ)=(2.3±0.6)×10^-2 and(1.35±0.18)×10^-3,respectively,and extract the ratio of the fragmentation fractions to be fc/fu=(6.4±1.9)×10^-3.展开更多
In this paper,we calculate the B_(c)→J/ψhelicity form factors(HFFs)up to twist-4 accuracy by using the light-cone sum rules(LCSR)approach.After extrapolating those HFFs to the physically allowable q^(2)region,we inv...In this paper,we calculate the B_(c)→J/ψhelicity form factors(HFFs)up to twist-4 accuracy by using the light-cone sum rules(LCSR)approach.After extrapolating those HFFs to the physically allowable q^(2)region,we investigate the B_(c)^(+)-meson two-body decays and semi-leptonic decays B_(c)^(+)→J/ψ+(P,V,ℓ^(+)ν_(ℓ)),where P/V stand for light pseudoscalar and vector mesons,respectively.The branching fractions can be derived using the CKM matrix element and the B_(c)lifetime from the Particle Data Group,and we obtain B(B^(+)_(c)→J/ψπ^(+))=(0.136+0.002−0.002)%,B(B^(+)_(c)→J/ψK^(+))=(0.010+0.000−0.000)%,B(B^(+)_(c)→J/ψρ+)=(0.768+0.029−0.033)%,B(B^(+)_(c)→J/ψK^(∗+))=(0.043+0.001−0.001)%,B(B^(+)_(c)→J/ψ_(μ)+ν_(μ))=(2.802+0.526−0.675)%and B(B^(+)_(c)→J/ψτ^(+)ν_(τ))=(0.559+0.131−0.170)%.We then obtain R_(π^(+)/μ+ν_(μ))=0.048+0.009−0.012 and R_(K^(+)/π^(+))=0.075+0.005−0.005,which agree with the LHCb measured value within 1σ-error.We also obtain R_(J/ψ)=0.199+0.060−0.077,which like other theoretical predictions,is consistent with the LHCb measured value within 2σ-error.These imply that the HFFs under the LCSR approach are also applicable to the B+c meson two-body decays and semi-leptonic decays B+c→J/ψ+(P,V,ℓ^(+)ν_(ℓ)),and the HFFs obtained using LCSR in a new way implies that there may be new physics in the B_(c)→J/ψℓ^(+)ν_(ℓ)semi-leptonic decays.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.10575052,10605012,and 10735080
文摘By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next- to-leading-order (NLO) contributions to the two-body charmless hadronic decays B^+ →ρ^+η(') and B^0 → ρ^0(ω, φ)η('), induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that (a) for B^± → ρ^±η(') (B^0 → ρ^0(ω, φ)η(')decays, the partial NLO contributions to branching ratios are small (large) in magnitude; and (b) the pQCD predictions for ACP^dir(B^± → ρ^±η(')) are consistent with the data, while the predicted .ACP(B^0 → ρ^0(ω)η(')) are generally large in magnitude and could be tested by the forthcoming LHCb experiments.
文摘The phenomenological non-relativistic quark model (NRQM) has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential (OGEP). An overall agreement is obtained with the experimental masses and decay widths.
文摘Majorana zero modes in the hybrid semiconductor-superconductornanowire is one of the promising candidates for topologicalquantum computing. Recently, in nanowires with a superconductingisland, the signature of Majorana zero modescan be revealed as a subgap state whose energy oscillatesaround zero in magnetic field. This oscillation was interpretedas overlapping Majoranas. However, the oscillation amplitudeeither dies away after an overshoot or decays, sharply oppositeto the theoretically predicted enhanced oscillations for Majoranabound states, as the magnetic field increases. Several theoreticalstudies have tried to address this discrepancy, but arepartially successful. This discrepancy has raised the concernson the conclusive identification of Majorana bound states, andhas even endangered the scheme of Majorana qubits basedon the nanowires.
基金Supported by the National Natural Science Foundation of China under Grant No. 10975184
文摘In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonie decays of the orbitally P-wave excited Bs meson states Bs*, including the newly found narrow Bs1 (5830) andBs2(5840) states, into the (Ds1(2536), Ds2(2573)) doublet are calculated from QCD sum rules. With these universal form factors, the decay rates and branching ratios are also estimated.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10575052, 10605012, and 10735080
文摘In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (i) The leading order pQCD predictions for the branching ratio Br(B^+→K^+K0^*(1430)^0)are in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered B→K0^*(1430)K decay modes are also presented and will be tested by the LHC experiments; (ii) The annihilation contributions play an important role in these considered decays, for B^0→K0^*(1430)^±K^± decays,for example,which are found to be (1-4)×10^-6.
基金the National Natural Science Foundation of China under
文摘Amplitudes for φ(2S) sequential decays into 2(π^+π^-)pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles in laboratory system. The results can be taken as a reference for measuring the decay of XCJ into at BESⅡ/BEPC in the near future.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11275088 and 11747318
文摘Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles and appear in many extensions of the Standard Model.Taking into account constraints on the free parameters from existing searches and explaining the g-2 deviation,we consider the contributions of ALPs with mass in the range of 1.5GeV
文摘To solve the/a problem of the Minimal Supersymmetric Standard Model (MSSM), a single field S is added to build the Next Minimal Supersymmetric Standard Model (NMSSM). Vacuum enlarged with non-zero vevs of the neutral-even CP is the combination of Hu, Hd and S. In the NMSSM, the Higgs sector is increased to 7 (compared with 5 hogs in the MSSM), including three Higgs-which are the even-CP hi,2,3 (mh1〈 mh2〈 mh3), two Higgs-which are odd-CP a1,2 (ma1 〈 ma2) and a couple of charged Higgs H^±. The decays Higgs into Higgs is one of the remarkable new points of the NMSSM. In this paper, we study the decays H^± into W^± and at. The decay width is calculated to one loop vertex correction. The numerical results are also described together with evaluations.
文摘This paper purposes an explanation for the recent evidence for the violation of lepton universality in beauty-quark decays at CERN’s Large Hadron Collider. A beauty meson (B<sup>+</sup>) transforms into a strange meson (K<sup>+</sup>) with the emission of either electron-positron (e<sup>+</sup>e<sup>-</sup>) or muon-antimuon (<span style="white-space:nowrap;"><em>μ</em></span><sup>+</sup><em>μ</em><sup>-</sup>). The ratio (<em>R</em><sub>K</sub>) of branching fractions for B<sup>+ </sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>- </sup>and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>-</sup> decays is measured to be <em>R</em><sub>K</sub> = 0.846 instead of 1 in the violation of lepton universality in the Standard Model. This paper proposes that the violation is derived from the binary isotope mixture of two beauty-quarks, b<sub>7</sub> (4979 MeV mass) and b<sub>8</sub> (143,258 MeV mass) whose masses are calculated from the periodic table of elementary particles. b<sub>7</sub> is the observable B, while b<sub>8</sub> is the hidden B to preserve the generation number symmetry between the three lepton family generations and the three quark family generations in the Standard Model. The preservation of the generation number symmetry forbids b<sub>8</sub> to decay into K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>. In the transition state involving the virtual particles (<span style="white-space:nowrap;"><em>γ</em></span>, W± and Z<span style="white-space:nowrap;">°</span>) before the decay, b<sub>7</sub> and b<sub>8</sub> emerge to form the binary isotope mixture from B. The rates of emergence as the rates of diffuse in Graham’s law of diffusion are proportional to inverse square root of mass. The rate ratio between b<sub>8</sub>/b<sub>7</sub> is (4979/143,258)<sup>1/2</sup> = 0.1864. Since b<sub>7</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, while b<sub>8</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and forbidden <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, the calculated ratio (RK) of branching fractions for B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup> and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>- </sup>is 0.5/(0.1864 × 0.5+ 0.5) = 0.843 in excellent agreement with the observed 0.846. The agreement between the calculated RK and the observed RK confirms the validity of the periodic table of elementary particles which provides the answers for the dominance of matter over antimatter, dark-matter, and the mass hierarchy of elementary particles.
基金Supported in part by the National Key R&D Program of China(2020YFA0406300,2020YFA0406400)the National Natural Science Foundation of China(NSFC)(11625523,11635010,11735014,11835012,11935015,11935016,11935018,11961141012,12025502,12035009,12035013,12061131003,12105276,12122509,12192260,12192261,12192262,12192263,12192264,12192265,12221005,12225509,12235017)+15 种基金the Chinese Academy of Sciences(CAS)Large-Scale Scientific Facility Programthe CAS Center for Excellence in Particle Physics(CCEPP)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U1732263,U1832103,U1832207,U2032111)CAS Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH003,QYZDJ-SSW-SLH040)100 Talents Program of CASThe Institute of Nuclear and Particle Physics(INPAC)and Shanghai Key Laboratory for Particle Physics and CosmologyEuropean Union's Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant agreement(894790)German Research Foundation DFG(455635585),Collaborative Research Center CRC 1044,FOR5327,GRK 2149Istituto Nazionale di Fisica Nucleare,ItalyMinistry of Development of Turkey(DPT2006K-120470)National Research Foundation of Korea(NRF-2022R1A2C1092335)National Science and Technology fund of MongoliaNational Science Research and Innovation Fund(NSRF)via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation of Thailand(B16F640076)Polish National Science Centre(2019/35/O/ST2/02907)The Swedish Research CouncilU.S.Department of Energy(DE-FG02-05ER41374)。
文摘Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D^(0)→a_(1)(1260)π,D^(0)→π(1300)π,D^(0)→ρ(770)ρ(770),and D^(0)→2(ππ)_(S)are observed in both channels.With the obtained amplitude model,the CP-even fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are determined to be(75.2±1.1_(stat).±1.5_(syst.))%and(68.9±1.5_(stat).±2.4_(syst.))%,respectively.The branching fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are measured to be(0.688±0.010_(stat.)±0.010_(syst.))%and(0.951±0.025_(stat.)±0.021_(syst.))%,respectively.The amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D^(0)→4πwhen used to determine the CKM angleγ(ϕ_(3))via the B^(−)→DK^(−)decay.
基金Supported by the National Natural Science Foundation of China(12075074,12235008,11535002,11705045)the Natural Science Foundation for Distinguished Young Scholars of Hebei Province,China(A2022201017)+1 种基金the Natural Science Foundation of Guangxi Autonomous Region(2022GXNSFDA035068)the Youth Top-NotchTalent Support Programof theHebei Province,China。
文摘We investigate the two loop electroweak corrections to B meson rare decays B¯→Xsγand B0s→μ+μ−in the minimal supersymmetry standard model(MSSM)extension with two triplets and one singlet(TNMSSM).The new particle contents and interactions in the TNMSSM can affect the theoretical predictions of the branching ratios Br(B¯→Xsγ)and Br(B0s→μ+μ−),and the corrections from two loop diagrams to the process B¯→Xsγcan reach around 4%.Considering the latest experimental measurements,the numerical results of Br(B¯→Xsγ)and Br(B0s→μ+μ−)in the TNMSSM are presented and analyzed.The findings indicate that the results in the TNMSSM can fit the updated experimental data well,and the new parameters Tλ,κ,λ,clearly affect the theoretical predictions of Br(B¯→Xsγ)and Br(B0s→μ+μ−).
基金Supported by the National Natural Science Foundation(12175068)and the Fundamental Research Funds for the Central Universities of China。
文摘In this study,considering the conservation of isospin in the strong decays,we investigate the strong decays of the pentaquark molecule candidate P_(c)(4312)and its possible higher isospin cousin P_(c)(4330)in the framework of the QCD sum rules.Further,the pole residue of theΔbaryon with isospin eigenstate|II3>=|3/21/2)is obtained.If the possible pentaquark molecule candidate P_(c)(4330)could be determined,it would shed light on the interpretations of the P_(c) states in future experiments.
基金Supported in part by the Natural Science Foundation of China(12335003)the Fundamental Research Funds for the Central Universities(lzujbky-2024-oy02,lzujbky-2023-it12)。
文摘There is a long-standing puzzle that the CP violation(CPV)in the baryon systems has never been wellestablished in experiments,while the CPV of mesons have been observed by decades.In this paper,we propose thatthe CpV of baryon decays can be generated with the rescatterings of a nucleon and a pion into some final states,i.e Nπ→Nπor Nππ.Benelited by the fruitful data of Nπscatterings,we can model-independently analyse the strongphases of b-baryon decays using the partial wave amplitudes of Nπscatterings.Avoiding the most difficult problemof non-perturbative dynamics,it makes a great advantage to predict the CpV of baryon decays with a relatively reli.able understanding of the decay dynamics.We study the processes of∧_(b)^(0)→(pπ^(+)π^(-))h^(-)and(pπ^(0))h^(-)with h=πor K.It is found that the global CPV of the above processes in the invariant mass regions of Nπscatterings are at theorder of several percent.More importantly,the local CPV in some regions of the Dalitz plots can reach the order of 10%,or be even larger.Considering the predicted results and the experimental data samples,we strong suggest tomeasure the CPV of∧_(b)^(0)→(pπ^(+)π^(-))K^(-),which has a large possibility to achieve the first observation of CPV in thebaryon system.
基金Supported in part by the Open Project of Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry & Technology (XTKF-2020-01)the Nation-al Science Foundation of China (11705159,11975195)+1 种基金the Natural Science Foundation of Shandong province (ZR2019JQ04,ZR2022ZD26,ZR2020MA093)the Project of Shandong Province Higher Educational Science and Technology Program (2019KJJ007)。
文摘Using the perturbative QCD approach,we studied the effects of the hadronic structure of photons on the pure annihilation rediative decays B→φγ and B_(s)→(ρ^(0),ω)γ.These decays have small branching fractions due to the power suppression by Λ/mB,which makes them very sensitive to next-leading power corrections.The quark components and the related two-particle distribution amplitudes of a final state photon are introduced.The branching fractions can be enhanced remarkably by factorizable and nonfactorizable emission diagrams.The branching fraction of B→φγ increases by approximately 40 times,and those of B_(s)→ρ^(0)γ and B_(s)→ωγ are on the order of O(10-10).We also note that the ratio of branching fractions of B_(s)→ρ^(0)γ and B_(s)→ωγ is very sensitive to the effects of the hadronic structure of photons.All these results can be tested in future.
基金Supported in part by the National Natural Science Foundation of China(11575175,12047502)National Research and development Program of China(2020YFA0406400)。
文摘Within the standard model,we have investigated rare Z-boson decays into double heavy quarkonia,Z→VV and Z→VP,with V and P denoting vector and pseudo scalar quarkonia,respectively.It is assumed that the leading-order QCD diagrams would give the dominant contributions to these processes,and the corresponding branching fractions,for instance,B(Z→J/ΨJ/Ψ),have been estimated to be approximately 10^(-13)in literature.However,these decays could also happen through electromagnetic transitions Z→Vγ^(*)and Z→Pγ^(*),with the virtual photon transforming into V.Interestingly,the smallness of the vector quarkonium mass can give rise to a large factor m_(Z)^(2)/m_(V)^(2)relative to the QCD contributions,which thus counteracts the suppression from the electromagnetic coupling.We systematically include these two types of contributions in our calculation to predict branching fractions for these decays.Particularly,owing to the virtual photon effects,it is found that B(Z→J/ΨJ/Ψ)will be significantly enhanced,up to 10^(-10).
基金Supported by the National Natural Science Foundation of China(11347030)the Program of Science and Technology Innovation Talents in Universities of Henan Province,China(14HASTIT037)the Natural Science Foundation of Henan Province,China(232300420116)
文摘In this work,we investigate the quasi-two-body decays B_(c)→D^(*)h→Dπhwithh=(K^(0),π^(0),η,η′)using the perturbative QCD(PQCD)approach.The description of final state interactions of the Dπpair is achieved through the two-meson distribution amplitudes(DAs),which are normalized to the time-like form factor.The PQCD predictions on the branching ratios of the quasi-two-body decays B_(c)→D^(*)h→Dπh show an obvious hierarchy:Br(B^(+)_(c)→D^(∗+)K^(0)→D^(0)π^(+)K^(0))=(5.22^(+0.86)_(-0.74))×10^(-6),Br(B^(+)_(c)→D^(∗+)π^(0)→D^(0)π^(+)π^(0))=(0.93±0.26)×10^(-7),Br(B^(+)_(c)→D^(∗+)η→D^(0)π^(+)η)=(2.83^(+0.59)_(-0.52))×10^(-8)and Br(B^(+)_(c)→D^(∗+)η′→D^(0)π^(+)η′)=(1.89+0.40-0.36)×10^(-8).From the invariant mass m Dπ-dependence of the decay spectrum for each channel,one can find that the branching fraction is concentrated in a narrow region around the D*pole mass.Thus,one can obtain the branching ratios for the corresponding two-body decays B_(c)→D^(*+)h under the narrow-width approximation.We find that the branching ratios of the decays B_(c)→D^(*+)h are consistent with the previous PQCD calculations within errors.These predictions will be tested in future experiments.
基金Supported by the National Natural Science Foundation of China(11235005,11847141,12105112)the Natural Science Foundation of Jiangsu Education Committee(21KJB140027)the Natural Science Foundation of Huaiyin Institute of Technology(21HGZ012)。
文摘Within the framework of perturbative QCD factorization,we investigate the nonfactorizable contributions to the factorization-forbidden quasi-two-body decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=π,K.We compare our predicted branching ratios for the B_(()(s))→K_(χc0)→Kπ^(+)π-(K^(+)K^(-))decay with available experiment data as well as predictions by other theoretical studies.The branching ratios of these decays are consistent with data and other theoretical predictions.However,in the Cabibbo-suppressed decays B_((s))→h_((χ)_(c0))→hπ^(+)π^(-)(K^(+)K^(-))with h=K^(0),π,the values of the branching ratios are of the order of 10^(-7)and 10^(-8).The ratio R_((χ)_(c0))between the decays B^(+)→π^(+)χ_(c0)→π^(+)π^(+)π^(-)and B^(+)→K^(+)χc0→K^(+)π^(+)π^(-)and the distribution of branching ratios for different decay modes in invariant mass are considered in this study.
基金supported in part by the National Natural Science Foundation of China (11735003, 11975041, and11961141004)support from the National Natural Science Foundation of China (12147145)+2 种基金support from the National Natural Science Foundation of China (12105006)Project funded by China Postdoctoral Science Foundation (2021M700343)China Postdoctoral Science Foundation (2021M690008)
文摘Weak radiative hyperon decays,important to test the strong interaction and relevant in searches for beyond the standard model physics,have remained puzzling both experimentally and theoretically for a long time.The recently updated branching fraction and first measurement of the asymmetry parameter of Λ→nγ by the BESIII Collaboration further exacerbate the issue,as none of the existing predictions can describe the data.We show in this work that the covariant baryon chiral perturbation theory,with constraints from the latest measurements of hyperon non-leptonic decays,can well describe the BESIII data.The predicted branching fraction and asymmetry parameter for Ξ→Σγ are also in agreement with the experimental data.We note that a more precise measurement of the asymmetry parameter,which is strongly constrained by chiral symmetry and related with that of Σ→pγ,is crucial to test Hara’s theorem.We further predict the branching fraction and asymmetry parameter of Σ~0→nγ,whose future measurement can serve as a highly nontrivial check on our understanding of weak radiative hyperon decays and on the covariant baryon chiral perturbation theory.
基金Supported in part by National Center for Theoretical Sciences,National Science Council(NSC-101-2112-M-007-006-MY3)MoST(Mo ST-104-2112-M-007-003-MY3)National Science Foundation of China(11675030)
文摘We study two-body B(c)→Mc(π,K) and semileptonic Bc→Mcl^-v^-1 decays with Mc=(J/φ,Xc^0),where Xc^0=X^0(3872) is regarded as the tetraquark state ccuu(dd).With the decay constant fxc^0=(234±52) MeV determined from the data,we predict that B(B^-→Xc^0π^-) =(11.5±5.7)×10^-6,B(B^0→Xc^0K^-0)=(2.1±1.0)×10^-4,and B(Bs^0→Xc^0K^0)=(11.4±5.6)×10^-6.With the form factors in QCD models,we calculate that B(Bc^-→Xc^0π^-,Xc^0K^-)=(6.0±2.6)×10^-5 and(4.7±2.0)×10^-6,and B(Bc^-→J/φμ^-vμ^-vμ,Xc^0μ^-v^-μ)=(2.3±0.6)×10^-2 and(1.35±0.18)×10^-3,respectively,and extract the ratio of the fragmentation fractions to be fc/fu=(6.4±1.9)×10^-3.
基金Supported in part by the National Natural Science Foundation of China(11765007,11625520,11947406,12047564)the Project of Guizhou Provincial Department of Science and Technology(KY[2019]1171)+4 种基金the Project of Guizhou Provincial Department of Education(KY[2021]030)the China Postdoctoral Science Foundation(2019TQ0329,2020M670476)the Chongqing Graduate Research and Innovation Foundation(ydstd1912)the Fundamental Research Funds for the Central Universities(2020CQJQY-Z003)the Project of Guizhou Minzu University(GZMU[2019]YB19)。
文摘In this paper,we calculate the B_(c)→J/ψhelicity form factors(HFFs)up to twist-4 accuracy by using the light-cone sum rules(LCSR)approach.After extrapolating those HFFs to the physically allowable q^(2)region,we investigate the B_(c)^(+)-meson two-body decays and semi-leptonic decays B_(c)^(+)→J/ψ+(P,V,ℓ^(+)ν_(ℓ)),where P/V stand for light pseudoscalar and vector mesons,respectively.The branching fractions can be derived using the CKM matrix element and the B_(c)lifetime from the Particle Data Group,and we obtain B(B^(+)_(c)→J/ψπ^(+))=(0.136+0.002−0.002)%,B(B^(+)_(c)→J/ψK^(+))=(0.010+0.000−0.000)%,B(B^(+)_(c)→J/ψρ+)=(0.768+0.029−0.033)%,B(B^(+)_(c)→J/ψK^(∗+))=(0.043+0.001−0.001)%,B(B^(+)_(c)→J/ψ_(μ)+ν_(μ))=(2.802+0.526−0.675)%and B(B^(+)_(c)→J/ψτ^(+)ν_(τ))=(0.559+0.131−0.170)%.We then obtain R_(π^(+)/μ+ν_(μ))=0.048+0.009−0.012 and R_(K^(+)/π^(+))=0.075+0.005−0.005,which agree with the LHCb measured value within 1σ-error.We also obtain R_(J/ψ)=0.199+0.060−0.077,which like other theoretical predictions,is consistent with the LHCb measured value within 2σ-error.These imply that the HFFs under the LCSR approach are also applicable to the B+c meson two-body decays and semi-leptonic decays B+c→J/ψ+(P,V,ℓ^(+)ν_(ℓ)),and the HFFs obtained using LCSR in a new way implies that there may be new physics in the B_(c)→J/ψℓ^(+)ν_(ℓ)semi-leptonic decays.